Avian Virus Growths and their Etiologic Agents

Beard, J. W.

doi:10.1016/s0065-230x(08)60982-3

Cited by 119 publications

(39 citation statements)

References 148 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The virion was collected from the top of the glycerol pad and diluted with 0.1 M NaCl-1 mM Tris (pH 7.4)-i mM EDTA. The virus was purified further after two cycles of differential centrifugation (17).…”

Section: Methodsmentioning

confidence: 99%

Base Composition Differences between Avian Myeloblastosis Virus Transfer RNA and Transfer RNA Isolated from Host Cells

Randerath

Rosenthal

Zamecnik

1971

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

Using a novel chemical tritium derivative method, we have determined the base composition of 4S RNA isolated from an RNA tumor virus, the avian myeloblastosis virus, and from normal and neoplastic host cells. Extensive differences were detected, particularly with respect to the amount of methylated bases in the viral RNA. The (7), with respect to the four major bases: adenine, guanine, cytosine, and uracil. No quantitative data on modified ("minor") bases have, however, been reported thus far for 4S RNA from any RNA tumor virus. 4S RNA from AMV does not have the same amino acid-accepting activity as host-cell 4S RNA (2, 3, 6), and lysine tRNA elution profiles have been shown to differ (9).We report in this communication major and minor base constitution data for normal chicken liver, myeloblast, and AMV 4S RNA. Base composition was analyzed by a novel isotope derivative method, which involves the stoichiometric incorporation of tritium label into periodate-oxidized enzymatic digests of RNA, chromatographic resolution of such labeled digests into individual radioactive nucleoside derivatives, and evaluation by liquid-scintillation counting (10)(11)(12)(13)(14). Due to its sensitivity, this method is capable of assaying minute amounts of RNA (<1 Mg) without requiring in vivo labeling of the RNA with isotopes. MATERIALS AND METHODSVirus Growth and Purification. Avian myeloblastosis virus, Beard's BAI strain A, was propagated by intraperitoneal injection of 1-day-old White Leghorn chickens (15) (Spafas, Inc., Norwich, Conn.). The morphology of peripheral blood was observed by Wright-stained smears. Plasma was obtained by cardiac puncture (heparin was used as an anticoagulant) from chickens with advanced leukemia. The virus was purified by centrifugation of plasma that contained 101I1012 viral particles per ml at 7500 rpm for 10 min in a Sorvall RC-2B refrigerated 40C centrifuge. The supernatant plasma was layered onto the top of 100% glycerol pads and centrifuged at 50C for 90 min at 29,000 rpm in a Spinco no. 30 rotor (16). The virion was collected from the top of the glycerol pad and diluted with 0.1 M NaCl-1 mM Tris (pH 7.4)-i mM EDTA. The virus was purified further after two cycles of differential centrifugation (17).Isolation of Viral RNA. Viral RNA was isolated from purified preparations of AMV by either of two methods. In the first, purified virus from 300 ml of plasma was extracted according to the procedure described by Travnicek (3). The portion of RNA that was soluble in 2 M NaCl was designated as crude viral tRNA (3), which was further purified by Sephadex column chromatography, as described below. A final yield of 120 1g of purified 4S RNA was obtained.The second method for extraction of the viral RNA used a buffering system described by Duesberg (18). Purified viral pellets were obtained from 650 ml of plasma. The second method appears to be preferable because of better preservation of m7G (see Results section). 320 ,ug of purified 4S RNA were obtained after purification by column chromatogr...

show abstract

Section: Methodsmentioning

confidence: 99%

Base Composition Differences between Avian Myeloblastosis Virus Transfer RNA and Transfer RNA Isolated from Host Cells

Randerath

Rosenthal

Zamecnik

1971

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…This property was developed into an end-point titration assay and hundreds of thousands of chickens were used to purify and study the virus (reviewed in Beard, 1963). Following the introduction of a cell culture assay for RSV by Rubin and Temin, similar assays were developed for AMV (Baluda and Goetz, 1961).…”

Section: Cells and Transformation Assays (Figure 2)mentioning

confidence: 99%

“…In particular, although both Rous sarcoma virus (RSV) and AMV could replicate in cultures of either embryonic ®broblasts or hematopoietic cells, RSV could transform only ®broblasts whereas AMV could transform only hematopoietic cells (Baluda, 1963;Durban and Boettiger, 1981a). Second, chickens infected with AMV develop remarkably high white counts and therefore their peripheral blood contains remarkably large quantities of viral particles (Beard, 1963). For this reason AMV was often used as a prototypic retrovirus in order to study viral assembly and later to produce large amounts of reverse transcriptase for both research and commercial purposes.…”

mentioning

confidence: 99%

Transformation by v-Myb

1999

View full text Add to dashboard Cite

“…Whereas the avian myeloblastosis virus (AMV) containing the v-myb oncogene exclusively induces myeloblastosis (1,17,18), E26 exhibits a dual-target cell specificity for hematopoietic cells and is able to transform both avian myeloblasts and erythroblasts in vitro. When inoculated into chickens, E26 induces a mixed erythroid-myeloid leukemia, although proliferation of erythroid elements predominates (10,11,18,24).…”

mentioning

confidence: 99%

The proto-oncogene c-ets is preferentially expressed in lymphoid cells.

Chen¹

1985

Mol. Cell. Biol.

View full text Add to dashboard Cite

The transforming sequences of the avian acute leukemia virus, E26, contain two distinct oncogenes, v-mybE and v-ets, fused together. By using a probe containing v-ets sequences, polyadenylated transcripts of the c-ets proto-oncogene were detected in avian tissues; they included a major 7.0-kilobase and a minor 2.0-kilobase species. These c-ets mRNAs were detected at high levels only in lymphoid organs and in avian T and B lymphoid cell lines. A similar pattern of c-ets transcription was observed in human hematopoietic cell lines, with transcripts detected in lymphoid B and T cells but not in erythroid or myeloid cells. The E26 oncogene was inserted into an inducible expression vector, and a 90-kilodalton protein (bp9O) was produced in bacteria. Rabbit antisera raised to purified bp9O precipitated p135gamYybEets, the v-mybE-ets polyprotein expressed in E26-transformed cells, and also reacted with p50vmsbA, the transforming protein of the avian myeloblastosis virus. Antiserum to bp9O was absorbed with a bacterially synthesized v-mybA protein to remove anti-myb activity. The absorbed anti-bp9O serum retained the ability to immunoprecipitate p135gag9-YbetS from E26-transformed cells and specifically reacted with a 56-kilodalton polypeptide (p56) detected in chicken lymphoid organs and in T and B lymphocytes of both avian and human origin. The data suggest that p56 is a translational product of the c-ets proto-oncogene and imply that p56 may be involved in regulating the growth of lymphoid cells.

show abstract

Avian Virus Growths and their Etiologic Agents

Cited by 119 publications

References 148 publications

Base Composition Differences between Avian Myeloblastosis Virus Transfer RNA and Transfer RNA Isolated from Host Cells

Base Composition Differences between Avian Myeloblastosis Virus Transfer RNA and Transfer RNA Isolated from Host Cells

Transformation by v-Myb

The proto-oncogene c-ets is preferentially expressed in lymphoid cells.

Contact Info

Product

Resources

About